Information technology advancements such as real-time multimedia applications and high-speed Internet access, as well as the integration of common communications means such as telephone, Internet, television, and digital data systems have led to an unprecedented need for high-speed data transfer. However, many segments of today's wired networks are incapable of supporting the transfer rates required by these technologies. In many cases, it is impractical, both physically and economically, to install the necessary fiber optic and other broadband infrastructures to overcome this deficiency. Furthermore, in certain circumstances such as emergencies and military operations requiring high-speed data transfer, there exists an inherent need for rapid and temporary network access deployment without a physical infrastructure
Although wireless data transfer methods exist today, current technologies, including today's fastest radio modems, are limited to speeds approximating a T3 communication line, or about 45 megabits per second. Current high-speed physical transfer mediums, both optical and wired, however, are often much faster, affording data transfer rates of several gigabits per second and beyond. Consequently, segments of today's networks that are not connected with a high-speed physical transfer medium act as bottlenecks with respect to the rest of the system.
Therefore, the primary object of this invention is to provide new fixed wireless channel multiplexing techniques and system architecture to overcome these limitations and to provide a system which yields data transfer rates from several megabits per second to multiple gigabits per second.
An example of a solution in which this invention may be incorporated is discussed in the pending application titled "Wideband Wireless Access Local Loop Based on Millimeter Wave Technology" by Izadpanah, et al., attorney docket number HRL1, which is incorporated herein by reference, and which identifies how the need for greater bandwidth has created a bottleneck in user access and in approximately the first and/or last mile of many fixed wireless networks. Traditionally, Local to Multipoint Distribution Services (LMDS) and Multi-channel Multipoint Distribution Services (MMDS) have been used to overcome these bottlenecks and to deliver video programs for education and entertainment in an analog format, with broadcast radii of one to five miles, and ten to forty miles, respectively. With the increasing acceptance of digital video and video compression methods alongside the increased system capacity, the need for two-way high-bandwidth transmissions in digital form is gaining importance. Unfortunately, although current LMDS and MMDS systems are capable of offering data transmission rates of up to several gigabits per second, they are designed for one-way distribution, not for two-way broadband applications. Therefore, they fail to fulfill the need for two-way transmissions to areas where there is no suitable infrastructure. Furthermore, because of their logistical and equipment requirements, they are designed for permanent emplacements and are of no use whatsoever in applications requiring rapid, wireless deployment.
In contrast, the present invention may be configured to provide a two-way broadband data transfer method, including a rapidly deployable and relatively low cost system architecture along with new channel multiplexing techniques for the provision of high-speed wireless data transfer links. This architecture is designed for implementation with minimal infrastructure requirements. Configured with the necessary supporting architecture, this system provides a means to overcome the transmission difficulties associated with current fixed wireless technologies. See e.g.:
1. H. Izadpanah, et al, "MM-Wave Wireless Access Technology For The Wideband Wireless Local Loop Applications," presented at the 1998 IEEE Radio and Wireless Conference (RAWCON'98), Colorado Springs, Colo., August 1998. PA1 2. H. Xu, et al, "The Sliding Correlator And Network Analyzer Channel Sounding Methods For Wideband Multipath Propagation Measurements At 5.85 GHz," Advancing Microwaves- 1998 Special Wireless Issue, Volume 25, No. 3, June 1998, pp. 17-27.
The system of the present invention may be configured in a manner such that it may deliver data to a fixed single user, or multiple users, at aggregate/peak gigabit per second rates.